Balance board



FIG. 1 is a first perspective view of a balance board showing my new design;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top view thereof;

FIG. 8 is a bottom view thereof;

FIG. 9 is a perspective view of another state of the balance board thereof;

FIG. 10 is a perspective view of another state of the balance board thereof; and,

FIG. 11 is an enlarged view of the selected portion 11 in FIG. 1.

The broken lines shown in the drawings depict portions of the balance board that form no part of the claimed design. 

CLAIM The ornamental design for a balance board, as shown and described. 